Welding machine



FIG. 1 is a perspective view of a welding machine showing my new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a side elevational view taken from the left of FIG. 1, the side opposite being a mirror image thereof;

FIG. 4 is a front elevational view thereof; and

FIG. 5 is a rear elevational view thereof. 

The ornamental design for a welding machine, as shown and described. 